Find the asymmetry first

Gray Cook and Lee Burton were two physical therapists who in 1997 got tired of watching athletes get hurt doing programs that were, on paper, perfectly designed. The problem wasn't the program. It was that nobody had checked whether the athlete could actually move well before loading them. So they built a screen: seven fundamental movement patterns, each scored from zero to three, that takes ten minutes and tells you where the body is compensating. The Functional Movement Screen.

The seven are a deep squat, a step over a hurdle, a lunge in line, a shoulder reach behind the back, a straight-leg raise lying down, a push-up with the trunk held stable, and a rotational stability test on hands and knees. A perfect score is twenty-one. What matters more than the total is two things: any pattern scored zero or one, which means pain or inability, and any asymmetry, where the left side scores differently from the right.

Asymmetry is the key. Cook's finding, repeated in studies on athletes, firefighters and soldiers, is that a body that moves differently on its two sides is a body headed for an injury. The weak side gets overloaded, the strong side compensates, and something eventually gives. Find the asymmetry before you train and you can fix it in weeks. Find it after and you're in rehab.

For the month of the Body, this key is the mirror the strength keys needed. You've been adding load for a month. Before you add more, ask: is the load going into a body that moves evenly? A certified screener can run the full seven in ten minutes. You can run the simplest version at home today.